Inveteracy (definition)

Firm establishment by long continuance; firmness or deep-rooted obstinacy of any quality or state acquired by time; as, the inveteracy of custom, habit, or disease; -- usually in a bad sense; as, the inveteracy of prejudice or of error.

An inveteracy of evil habits that will prompt him to contract more.
A. Tucker.

2.

Malignity; spitefulness; virulency.

The rancor of pamphlets, the inveteracy of epigrams, an the mortification of lampoons.
Guardian.